A doctor fatally injected his two children with drugs and attempted to take his own life, Nakuru police said.
He had argued on Saturday night with his young second wife, a medic who wished to travel abroad, a neighbour said.
The children were a boy, aged five, and a girl, aged three.
The doctor was identified as James Muriithi Gakara, 50, who is now hospitalised and under guard.
He is an obstetrician and gynaecologist, owner of Optimum Current Health Care Clinic along Kinuthia Mbugua Road.
From examining drugs on the bedside table, police said the children were probably injected with insulin, perhaps other drugs.
A sharp knife was also on the table.
Nakuru county police commander Beatrice Kiraguri said the physician then tried to commit suicide in his bedroom in upmarket Milimani estate.
Police went to the house after neighbours reported unusual occurrences at about 9.30pm on Saturday.
“The officers found the house locked from the inside, they had to break in and found the medic lying unconscious on his bed. The children’s bodies were in another bedroom,” Kiraguri said.
The doctor was admitted to Rift Valley Provincial General Hospital in stable condition.
“He has been stabilised and could speak on Sunday morning. He is in the ICU under tight police watch," Kiraguri said.
She said the motive was not clear and only a postmortem exam could determine the substances used for injections.
“The doctor’s wife had travelled to Nairobi and she was only called when the children were already dead,” the commander said.
Fewer than 10 days earlier, the clinic put up a poster on World Suicide Day, September 10, telling people what to do if they know someone who wants to take their own life.
"If someone is thinking about suicide, it should be taken seriously and nonjudgmentally. Help the individual seek a professional and do not leave them alone," read the post on the clinic's Facebook page.
A neighbour who sought anonymity said the doctor and his wife disagreed over her wish to travel abroad.
“The couple had a disagreement on Saturday evening and the wife left," the neighbour said.
A colleague described Gakara as a good-natured man, usually wearing a smile and often laughing with colleagues.
"No one could tell he had a problem," she said.
(Edited by V. Graham)
